Spark plug



T. F. HANWAY.

SPARK PLUG.

APPLICATION FILED FEB. Is, 1920.

Patented Feb. 7, 1922.

VE El? M W H F. @I m MMM 'UNITED STATES TH-OMAS F. HANWAY, F CHICAGG, ILLINOIS.

SPARK PLUG.

Specification of Letters Patent.

Application led February 16, 1920. Serial No. 359,094.

To all whom t ma concern.'

Be it known that THOMAS F. lIIniawmr, a citizen of the United States, and a resident of the city of Chicago, in the county of Cookl` and State of Illinois, have invented certain new and useful Improvements in a Spark Plug; and I do hereby declare thatV the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the numerals of reference marked thereon, which forni a part of this specification.

This invention relates to an improved form of spark plug wherein the central terminal or conductor extending through the insulating material of the plug, 'is' split at its lower end and yflares outwardly and with the outer or grounded terminals of the plug consisting `of two substantially semicircular ring elements secured into the metal portion of the plug and encircling the flared endsl of the central terminal, but out of contact therewith.A

It is an object therefore of this invention to provide a spark plug wherein a multiplicity of spark points are provided so that foulingof any' one or more of the terminal points cannot affect the sparking .operation of others thereof, and also providing' a umeans for producing a shower of sparks when all of the terminals function to permit the occurrence of sparks thereacross.

Other and further important objects of this invention will be apparent from the `disclosures in the drawingsand specification.

The invention (i a preferred form) is illustrated in the drl wings and hereinafter more fully described.

plug.

Description. The reference numeral l indicates a metal Patented Feb. 7, 192:2.v

lower port-ion of reduced diameter is threaded as indicated at 3 to permit attachment thereof into the spark plug aperture of an engine. Fitted into the tubular casing 1 is a porcelain or other insulating element 4 with a sealing asket of copper or other suitable material isposed between plug element and the casino' 1, and with a gland member 6 threaded into the upper portion of the tubular casing 1 and bearing downwardly upon the insulating element through another sealing gasket 7 to hold said element tightly and `sealingly within the tubular casing 1. Said insulating element is cored out on its interior and has inserted therethrough upwardly through the lower end thereof, a conductor or central terminal member 8. The lowerv end of said terminal member 8 is enlarged as indicated by the reference numeral 9 and at a point below, is split into four portions whic are bent outwardly each affording a prong-shaped spark terminal and ldenoted by the reference numeral 10. A sealing gasket 11 is fitted around the upper surface of the enlarged portion 9 to bear against the end of the recess in said insulating element 4 Aas clearly shown in Figure y2. At-its "upper end sai-d central terminal member 4 is squared as indicated by the reference numeral l2 and thereabove is cylindrical and threaded as indicated by the reference numeral 13.

Owing to thepeculiar shape of the cylindrical terminal element 4 it is' preferable to mold the insulating element therearound so that the two become permanently associated.

As shown in Figure 2, engaged ove-r the upper end of the terminal element 4 isa gasket or washer 14 and tted over, and

overlap-ping the upper end of the insulating element, and threaded on the' central terminal 4, is a small clamping nut 15. A wire terminal fitting 16 is threaded on the upper threaded end of the terminal member 4 and bears downwardly against said nut 15. The lower face of the threaded portion -3 of the tubular casing 1 is apertured at two points with pairs of apertures diametrically e bent ends 17 of semiclrcularly curved o ppositely dlsposed, and engaged therein are. t

vspark terminal members 18. Said terminal members 18 encircle the outwardly flared. spark terminals 10 and are spaced therefrom the proper spark-gap distance. The central terminal element 8 receivesthe ungrounded high-tension terminal of an ignition system connected thereto at the Wire terminal fitting 16.

-When the high-tension current is passed through said. terminal 8, a shower 'of .sparks occurs between the' spark terminals 10 and the spark terminals 18 which are connected in the metal portion or grounded parts of the spark plug. In the event that any of the spa-rk gaps between any one of the terminals 10 .and 18 become fouled so as to hinder the flashing of a spark thereacross', the necessary ignition spark will take place across the other terminals 10 and 18. A copper gasket or Washer 19 is provided to eil'ect a tight-litting connection between the casing 1 and the engine to which the spark plug is attached.

I am aware that numerous details of construction may be varied through a wide range Without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted other- Wise than necessitated by the prior art.

Ulam.

THOMAS F. I-IANWA Y. Witnesses EARL M.' HARDINE, OSCAR HARTMANN. 

